devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Heiner Kallweit <hkallweit1@gmail.com>
To: Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Wolfram Sang <wsa@kernel.org>, Peter Rosin <peda@axentia.se>
Cc: "linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>
Subject: [PATCH v5 0/3] i2c: gpio: support write-only sda
Date: Wed, 18 Jan 2023 22:49:48 +0100	[thread overview]
Message-ID: <6f4b54d9-ab6d-a4d4-5142-27c89e03c6d2@gmail.com> (raw)

There are slave devices that understand I2C but have read-only SDA and
SCL. Examples are FD650 7-segment LED controller and its derivatives.
Typical board designs don't even have a pull-up for both pins.
Therefore add properties for not using open-drain. For write-only SCL
we have a property already, add one for write-only SDA.

v2:
- improve commit message for patch 1

v3:
- patch 2: check for adap->getsda in readbytes()
- patch 2: align warning message level for info on missing getscl/getsda
- patch 3: improve description of attribute sda_is_output_only

v4:
- patch 1: add no-pullup properties
- patch 2: handle SDA and SCL independently
- patch 2: properly handle case that SDA is NULL but SCL not
- patch 3: handle new no-pullup attributes
v5:
- patch 1: add checking mutually-exclusive attributes to schema

Heiner Kallweit (3):
  dt-bindings: i2c-gpio: Add properties for dealing with write-only SDA/SCL w/o pullup
  i2c: algo: bit: allow getsda to be NULL
  i2c: gpio: support write-only sda/scl w/o pull-up

 .../devicetree/bindings/i2c/i2c-gpio.yaml     | 26 +++++++
 drivers/i2c/algos/i2c-algo-bit.c              | 77 +++++++++----------
 drivers/i2c/busses/i2c-gpio.c                 | 13 +++-
 include/linux/platform_data/i2c-gpio.h        |  9 +++
 4 files changed, 80 insertions(+), 45 deletions(-)

-- 
2.39.0


             reply	other threads:[~2023-01-18 21:50 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-18 21:49 Heiner Kallweit [this message]
2023-01-18 21:51 ` [PATCH v5 1/3] dt-bindings: i2c-gpio: Add properties for dealing with write-only SDA/SCL w/o pullup Heiner Kallweit
2023-01-23 21:08   ` Rob Herring
2023-01-23 22:20   ` Wolfram Sang
2023-01-18 21:54 ` [PATCH v5 2/3] i2c: algo: bit: allow getsda to be NULL Heiner Kallweit
2023-01-23 22:20   ` Wolfram Sang
2023-01-18 21:55 ` [PATCH v5 3/3] i2c: gpio: support write-only sda/scl w/o pull-up Heiner Kallweit
2023-01-23 22:21   ` Wolfram Sang
2023-01-20 10:27 ` [PATCH v5 0/3] i2c: gpio: support write-only sda Wolfram Sang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=6f4b54d9-ab6d-a4d4-5142-27c89e03c6d2@gmail.com \
    --to=hkallweit1@gmail.com \
    --cc=devicetree@vger.kernel.org \
    --cc=krzysztof.kozlowski+dt@linaro.org \
    --cc=linux-i2c@vger.kernel.org \
    --cc=peda@axentia.se \
    --cc=robh+dt@kernel.org \
    --cc=wsa@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).